How does Microsoft differentiate SQL Azure from SQL Server?
Unlike administration for an on-premise instance of SQL Server, SQL Azure abstracts the logical administration from the physical administration; you continue to administer databases, logins, users, and roles, but Microsoft administers the physical hardware such as hard drives, servers, and storage. This approach helps SQL Azure provide a large-scale multi-tenant database service that offers enterprise-class availability, scalability, security, and self-healing. Because Microsoft handles all of the physical administration, there are some differences between SQL Azure and an on-premise instance of SQL Server in terms of administration, provisioning, Transact-SQL support, programming model, and features. For more information see the Similarities and Differences – SQL Azure vs. SQL Server whitepaper.
